I've had second-hand experience trying to ship items back to US. It's not cheap! (Or fast). Dennis (the palm frond hat guy) and I were going to ship some of his hats for us to sell here. The postage, shipping, taxes, etc. made it WAY too expensive. If I remember correctly (this was four years ago), it was going to cost over US$200 to ship 10 hats to us here in Florida.
Things may have changed since then, but you might consider "shipping" your purchases by air. (i.e. check with your airline about shipping "freight". In the phone book, each airline will have a number, usually local, for their freight office.)
Another option is to check with the stores at the airport. They may ship purchases back to the States.
Hope this helps.

Is there anywhere in the Montego Bay Airport or the surrounding area where I can ship my purchases home? My husband and I will be first timers to Couples Negril July 25-30.

Don't know why you'd need to do that - certainly not a money-saving idea.....or time.....a postcard takes 2-3 weeks to get back to the States, packages can take longer. Take down an empty soft duffle bag in one of your suitcases and use it for carrying purchases home.

We bought a couple of carved wooden child sized chairs from a beach vendor at CN. We got an estimate of $196 to ship them to California! I bought a roll of tape at the gas station across the street from CN and packed the chairs in a box. We took it back as checked luggage without a problem. It was free since American Air allowed 2 checked bags per person and we only checked 3.

didn't realize it would be that expensive...I wanted to get one of the palm tree carvings at the CN gift shop for my girlfriend, but one of our bags zippers broke, so we had one less bag to get things home with. I was hoping maybe I could buy one directly from them and have it shipped. Oh well, maybe next time.